What does the archived alert establish?
A junior analyst at the fictional Alder Basin Energy reviews a closed reporting hour from an offshore site.
The question
An analytics model flagged an unusual pattern in the historical data. The set expects one source record per minute for 60 minutes. The analyst sends findings to the reliability supervisor.
| Records | |
|---|---|
| Source timestamps in the review hour | 12 |
| Values carried forward from earlier records | 48 |
Each current timestamp belongs to a different minute.
“Explain how much of the record supports the finding.”
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A strong answer, step by step
Open each step in turn. This is one strong answer, not the only one.
Step 1: How much of the hour is documented?
What would you do here? Open the move you’d make.
Count every displayed value as a current observation
Tempting, but it misses something. That counts 48 values copied from earlier records.
Count the 12 source records in the window
The strong move. Twelve of 60 expected records gives 20% coverage.
Treat the missing minutes as evidence that the pattern stopped
Tempting, but it misses something. The opening record gives no observations for those minutes.
See how a strong candidate says it
“The display has 60 values. Only 12 have source timestamps in the review hour, so current observations cover 20% of the hour.”
Why it works: Carried-forward values appear in the display without adding observations for the missing minutes.
Step 2: Does the second display confirm it?
An onshore summary shows the same pattern. Its source note says it reads the same cached feed as the first display.
What would you do here? Open the move you’d make.
Treat two displays as two independent sources
Tempting, but it misses something. They both read the same cached feed.
Ignore the second display and close the finding
Tempting, but it misses something. The shared source explains the agreement. The gap in the underlying data remains.
Trace both displays to their source and seek independent evidence
The strong move. The same feed can show the same pattern twice without corroborating it.
See how a strong candidate says it
“Both displays use one underlying source. I would record that link and ask for a distinct record from the same interval.”
Why it works: A second view can repeat the same gap or source error.
Step 3: How does the archive change the picture?
The verified archive returns 45 distinct records in minutes that were previously missing.
What would you do here? Open the move you’d make.
Count 45 recovered minutes and keep the remaining gap
The strong move. The 45 add to the 12 already observed, leaving three unobserved minutes.
Count all 60 because most of the archive is back
Tempting, but it misses something. Three expected records are still missing.
Add the recovered data to the original 60 displayed values
Tempting, but it misses something. Some of the original values were display fills for these same minutes.
See how a strong candidate says it
“We now have 57 of 60 records, or 95% coverage. I would refresh the retrospective assessment and keep the three missing minutes visible.”
Why it works: Each recovered record fills a different minute that had no current observation before.
Step 4: What can you tell the supervisor?
A site log recorded separately from both displays matches the pattern for six overlapping minutes. The reliability reviewer checked the log and left the cause open.
What would you do here? Open the move you’d make.
Report corroboration for the overlap and leave the cause open
The strong move. This states what the two sources show and gives the supervisor the limits of the finding.
Report that the log confirms the whole hour
Tempting, but it misses something. The independent log covers six minutes of that hour.
Label the pattern a confirmed physical fault
Tempting, but it misses something. The observed pattern and its cause are different questions.
See how a strong candidate says it
“The archive covers 57 of 60 minutes. An independent log matches the pattern for six overlapping minutes. I would send those facts, the gaps and the open question about cause to the reliability supervisor.”
Why it works: The log supports the pattern in its own interval. It does not give a diagnosis or confirm the whole hour.
The answer, in short
- Decision
- Brief the supervisor on source coverage and the independent overlap.
- Because
- Display values, current records and independent observations give different kinds of evidence.
- What would change it
- Independent evidence for more of the window could support a broader finding.
Common traps
- Check timestamps before counting records.
- Trace both views to their original source.
Check your answer
- I counted current records.
- I identified the shared feed.
- I kept the remaining gap visible.
- I explained the limit of the independent log.
Last reviewed Nov 11, 2026